Photographic film packs

ABSTRACT

The disclosure relates to photographic film packs containing a plurality of self-processing film units adapted to be exposed and withdrawn from the film pack in sequence. A novel arrangement of restraining tabs provided by the leader members of the respective film units insures proper sequential withdrawal of the film units and prevents the removal of each successive unit from effecting movement of any of the remaining units.

United States Patent Nerwin Mar. 14, 1972 [54] PHOTOGRAPHIC FILM PACKS[72] Inventor: Hubert Nerwin, Rochester, NY.

[73] Assignee: Eastman Kodak Company, Rochester,

[22] Filed: June 12, 1970 211 App]. No 45,686

[52] US. Cl ..95/19, 95/13 [51] Int. Cl. ..G03b 17/52 [58] Field ofSearch ..95/13, 19,22

[56] References Cited UNITED STATES PATENTS 2,930,299 3/ 1960 Land..95/22 X 2,978,971 4/1961 Ebum ..95/13 1,103,417 7/1914 Hopkins ..95/223,033,091 5/1962 Eloranta ..95/19 X 2,903,951 9/1959 Land ..95/19Primary Examiner.lohn M. l-loran Assistant ExaminerAlan A. MathewsAttorneyRobert W. Hampton and .l. Addison Mathews [57] ABSTRACT Thedisclosure relates to photographic film packs containing a plurality ofself-processing film units adapted to be exposed and withdrawn from thefilm pack in sequence. A novel arrangement of restraining tabs providedby the leader members of the respective film units insures propersequential withdrawal of the film units and prevents the removal of eachsuccessive unit from effecting movement of any of the remaining units.

7 Claims, 4 Drawing Figures 5 i l i i i n i Patented March 14, 1972 aimw n b 22 G a F d c h 7 NW 2 RT 33.%2% U m m m 5 2 HUBERT NERWIN 1INVENTOR.

ATTORNEYS PHOTOGRAPIIIC FILM PACKS BACKGROUND OF THE INVENTION 1. Fieldof the Invention The present invention relates to photography and moreparticularly to film packs containing a plurality of self-processingfilm units adapted to be exposed and withdrawn from the film pack insequence.

2. Description ofthe Prior Art A film pack of the type to which thepresent invention is directed comprises a folded assemblage of stackedfilm units located within an appropriate housing. Each such film unitincludes a film sheet and an image transfer or cover sheet. When thefilm pack is installed in a camera, the film sheets initially are insuperimposed relation to each other behind the cameras lens system sothat each such sheet can be exposed after the preceding one is moved outof exposure position. After each film sheet has been exposed, it ismoved into sandwiched relation with the corresponding cover sheet and alayer of processing fluid is distributed between the two sheets toinitiate development of the exposed image and to cause it to transfer tothe cover sheet, whereupon the continuing movement ofthe film unitremoves it from the camera.

Typically, superimposed leader members are attached to the respectivefilm units and are accessible from the exterior of the camera and can bemanually withdrawn to effect sequential processing and removal of thoseunits. As each film unit is moved, however, it is essential that theother film units remain in place. Accordingly, the superimposed trailingends of the film units are generally stapled to each other and to apressure plate member within the film pack housing so that only the filmunit being withdrawn will tear free of the staple.- The film assemblageis folded between the film sheets and the cover sheets so that thosesheets are generally parallel to each other. Therefore, if the trailingends of the film units are so attached to the pressure plate member, theforce that must be applied to the film unit being withdrawn issignificantly greater than that required to tear its trailing end freeof the housing because of the substantial friction developed betweenthat film unit and the adjacent film unit. Consequently, considerableeffort must be exerted to withdraw the successive film units which mustbe stronger and more securely attached to its housing element than wouldotherwise be necessary. Furthermore, such an arrangement does notnecessarily insure that the film units can be withdrawn only in propersequence.

The present invention relates to film packs of the same general typejust discussed but provides simple and reliable means for insuringsequential withdrawal of the film units therefrom and also forreleasably anchoring the leader mem bers of the film units adjacent theopening through which they emerge from the film pack housing so that theforce required to free each successive film unit does not substantiallyincrease the frictional engagement between the film and cover sheepportions of that unit and the corresponding portions of the succeedingunit. Briefly, this is accomplished in accordance with the invention byproviding the superimposed leader members with aligned integralanchoring tabs which are folded in approximately right angle relation tothe leader members in superimposed relation to each other. Thesuperimposed anchoring tabs are sandwiched between an inner surface ofthe housing wall that defines the opening for the leader members and theadjacent end surface of the pressure plate structure. Accordingly, theleader members cannot be withdrawn in improper sequence but can beremoved individually in proper sequence in opposition to the frictionalengagement of their respective anchoring tabs without danger of alsomoving one or more of the remaining film units. The trailing ends of thefilm units generally need not be attached to the pressure plate but ifsuch connection is desired it can be relatively insecure, thusminimizing the force required to withdraw the successive film units.

Various means for practicing the invention and other advantages andnovel features thereof will be apparent from the following detaileddescription of illustrative preferred embodiments of the invention,reference being made to the accompanying drawings in which likereference characters denote like elements.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a perspective view of a film pack according to the presentinvention.

FIG. 2 is a somewhat schematic cross-sectioned side elevational view ofthe film pack shown in FIG. 1 greatly exaggerated in thickness to depictthe construction and arrangement of the film units and the pressureplate structure within the film pack housing.

FIG. 3 is a fragmentary perspective view of the film pack depicted inFIGS. 1 and 2 shown partially broken away to illustrate the anchoringtabs associated with the respective film units.

FIG. 4 corresponds generally to FIG. 3 but illustrates an alternateembodiment of anchoring tabs.

DESCRIPTION OF THE PREFERRED EMBODIMENT As best illustrated by FIG. 1 ofthe accompanying drawings, a film pack 11 of the type to which thepresent invention relates comprises a box-like housing 12 which isillustrated as if it were lying on its fiat back wall member 13. A frontwall member 14 is supported in parallel relation to the back wall memberby side walls 15 and by end walls 16 and 17 and is provided with arectangular exposure window 18. A pressure plate assembly 19 withinhousing 12 comprises a flat front pressure plate 21 provided with acurved end portion 22 adjacent housing end wall 16 and a flat backpressure plate 23 including an end lip 24 adjacent and parallel tohousing end wall 17. A resilient leaf spring 25 connects the twopressure plates in generally parallel relation to each other and urgesthem apart to bias the front plate forwardly and the back platerearwardly.

By reference to FIG. 2, the film unit assemblage of the illustrativefilm pack will be seen to include four film units 260-26 comprisingrespective superimposed elongate leader members 27a-27d which are madeof heavy paper or the like and which extend through a slot 28 in endwall 17 of the housing. The trailing ends of the leader members arefolded past the curved end of pressure plate 21 and are attached torespective film sheets 29 provided with photosensitive surfaces facingwindow 18 in the front wall member of the housing. Additionally, aflexible connecting web 31 is attached to each pulling leader and alsoto the leading end of a corresponding cover or image transfer sheetlocated behind the pressure plate assembly. Initially, the film pack isalso provided with an opaque masking strip 32 located adjacent theoutermost film unit and covering exposure window 18 to prevent lightfrom reaching the film sheets. Like the leading ends of the leadermembers, the leading end of the masking strip also extends through slot28 so that it is likewise accessible from the exterior of the film packhousing.

As is well known in the prior art, a camera adapted to accommodate theillustrative film pack includes appropriate means for preventing lightfrom reaching the film pack exposure window 18 except through the cameralens and shutter.

The superimposed leading ends of the masking strip and the leadermembers extend between a pair of rollers or the like incorporated in thecamera and are accessible from the exterior of the camera housing. Afterthe film pack has been loaded into the camera, the photographer graspsthe leading end of the masking strip and withdraws the latter from thecamera. When the masking strip is thus removed, the resilient forward torearward expansion of the pressure plate assembly biases the margins ofthe forwardmost film sheet into contact with the inner surface of wallmember 14 to position the photosensitive surface of that sheet incoincidence with a focal plane of the camera lens system.

The leading ends of the leader members are provided with referencenumerals 33 or the equivalent to indicate the exposure sequence of therespective film sheets and are progressively shorter to facilitategrasping them in that sequence. After the first available film sheet hasbeen exposed, the photographer slowly withdraws the corresponding leadermember and thereby moves that sheet behind the pressure plate assemblyso that its exposed surface faces the forward surface of thecorresponding cover sheet. This movement of the film sheet absorbs allof the slack in the connecting web, thereby causing the film sheet andthe cover sheet to move together between the pressure rollers as thefilm unit is removed from the camera by the continuing withdrawal of itsleader member. A processing fluid pod 34 is attached to each leadermember adjacent the leading ends of the corresponding film sheet andcover sheets when the former has moved into alignment with the latter.When the processing fluid pod is drawn between the pressure rollers,processing fluid is squeezed out of the pod and is distributed betweenthe film sheet and the cover sheet as those sheets pass between therollers. An absorber pad or trap 35 at the trailing end of the coversheet is adapted to absorb excess processing fluid to preventcontinuation of the remaining film units. Upon coming into contact withthe film sheet, the processing fluid initiates development of theexposed image therein and causes that image to transfer to the coversheet, which can later be peeled away to provide the finishedphotograph. After each succeed ing film unit has been exposed, it isremoved and automatically processed in the same manner. Specific detailsof the construction and additional functions of the various elementscomprising the illustrative film units and alternate embodiments thereofhave been omitted from the present disclosure because such details arenot necessary to understanding the present invention and are readilyavailable from numerous prior art references relating to analogousself-processing film units.

As previously summarized, the present invention is directed to insuringthe withdrawal of the film units in proper sequence and to preventing anunexposed film unit from being moved by the withdrawal of the precedingexposed film unit or the masking strip. In accordance with the preferredembodiment of the invention illustrated by FIGS. 1-3, this objective isaccomplished by providing the respective leader member with integralanchoring tabs 36a-36d, which are formed simply die cutting a U-shapedincision through each leader member to define a tab or car that can befolded out of the plane of the surrounding leader material. During theassembly of the film pack, the film units are stacked in proper sequencewith their respective tabs or ears in mutual alignment, whereupon thelatter are folded in unison so that they extend forwardly from theleader members in superimposed relation to each other adjacent theresulting aligned leader member openings 37a-37. When the filmassemblage is installed in the film pack housing, the anchoring tabs aresandwiched between the inner surface of end wall 17 adjacent slot 28 andthe forwardly bent lip 24 of back pressure plate 23. By reference toFIG. 2, it will be apparent that anchoring tab 36a of the firstavailable film unit projects through openings 37b, 37c and 37d in thecorresponding leader members 27b, 27c and 27d of the subsequentlyavailable film units. Similarly, anchoring tabs 36b projects throughopenings 37c and 37d and anchoring tab 360 projects through opening 37d.

After the film pack is loaded into the camera, the masking strip iswithdrawn while the film units are returned in place by the sandwichedengagement of their anchoring tabs between the housing end wall and theend lip of the pressure plate assembly, which increases its grip on thetabs in response to the withdrawing force exerted on the masking strip.When the film sheet of film unit 26a has been exposed, the withdrawal ofleader member 27a pulls its anchoring tab 36a out of engagement betweenanchoring tab 36b and housing wall 17 and folds it back against theadjacent face of that leader member below leader member 27b as itemerges through slot 28. During the initial movement of leader member26a, frictional force tending to cause anchoring tab 36b to move withanchoring tab 36a is overcome by the bending resistance of tab 36b;thereby causing the latter to remain in its original position in whichit prevents movement of film unit 26b until the removal of film unit 26ais completed. The anchoring tabs of the remaining film units obviouslycooperate in the same manner as each succeeding film unit is withdrawn,thus insuring that only the exposed film unit is moved from its originalposition. If desired, it is also possible to provide the masking stripwith a similar anchoring tab, which is initially sandwiched between tab36a and housing wall 17.

If the photographer should attempt to pull the wrong leader member, itsmovement will be strongly resisted by the anchoring tabs of thepreceeding film units extending through the opening 37 therein, thusalerting him of his mistake. Accordingly, it will be seen that thepresent invention substantially insures proper sequential removal by thesuccessive film units and reduces the force required for that purposewhile at the same time simplifying the construction and assembly of thefilm pack.

The embodiment of the invention shown in FIG. 4 functions in the samemanner described above and is illustrated in conjunction with the samefilm pack housing 12 and pressure plate assembly 19. In accordance withthis embodiment, however, each of the four illustrative leader members38 is provided with two anchoring tabs 39 formed at the opposite edgesthereof by die-cut L-shaped incisions.

Although the foregoing disclosure is directed to specific illustrativeembodiments, it should be recognized that the invention is equallyapplicable to other types of conventional or self-processing film packsincluding those in which the removal of each subsequent film unit bringsthe leader member of the next unit to an accessible position.

The invention has been described in detail with particular reference toa preferred embodiment thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

Iclaim:

1. In a film pack comprising:

a box-like casing provided with an elongate leader slot and with anexposure window;

a first film sheet initially located within said casing in alignmentwith said exposure window, said first film sheet including a layer ofphotosensitive material for recording a processable latent image;

a second film sheet initially located within said casing in alignmentwith said first film sheet, said second film sheet including a layer ofphotosensitive material for recording a processable latent image;

pressure plate means resiliently biasing said film sheets toward saidexposure window;

a first elongate flexible leader member connected to said first filmsheet and initially positioned with its leading end portion extendingthrough said leader slot;

a second elongate flexible leader member connected to said second filmsheet and initially positioned with its leading end portion adjacent theinitial position of the leading end portion of said first leader member;

The improvement comprising:

means defining an opening in the leading end portion of one of saidleader members, and

means providing the leading end portion of said other leader member witha first anchoring tab which initially extends through said opening insaid one leader member within said casing.

2. The invention defined by claim 1 in which said first anchoring tabdefines a tip extending through said opening, said tip initially beingpositioned in normal relation to the leading end portion of the leadermember from which it extends and being positioned adjacent an internalsurface of said casing bordering said slot.

3. The invention defined by claim 1 in which said first anchoring tabcomprises an ear defined by an incision in the leading end portion ofsaid leader member from which it extends, said ear being folded out ofthe plane said last-mentioned leading end portion.

4. The invention defined by claim 2 in which said other leader member isprovided with a second anchoring tab corresponding to said firstanchoring tab, said second anchoring tab being initially positioned infacial engagement with the tip portion of said first anchoring tabextending through said opening in said one leader member.

5. The invention defined by claim 4 in which said first and

1. In a film pack comprising: a box-like casing provided with anelongate leader slot and with an exposure window; a first film sheetinitially located within said casing in alignment with said exposurewindow, said first film sheet including a layer of photosensitivematerial for recorDing a processable latent image; a second film sheetinitially located within said casing in alignment with said first filmsheet, said second film sheet including a layer of photosensitivematerial for recording a processable latent image; pressure plate meansresiliently biasing said film sheets toward said exposure window; afirst elongate flexible leader member connected to said first film sheetand initially positioned with its leading end portion extending throughsaid leader slot; a second elongate flexible leader member connected tosaid second film sheet and initially positioned with its leading endportion adjacent the initial position of the leading end portion of saidfirst leader member; The improvement comprising: means defining anopening in the leading end portion of one of said leader members, andmeans providing the leading end portion of said other leader member witha first anchoring tab which initially extends through said opening insaid one leader member within said casing.
 2. The invention defined byclaim 1 in which said first anchoring tab defines a tip extendingthrough said opening, said tip initially being positioned in normalrelation to the leading end portion of the leader member from which itextends and being positioned adjacent an internal surface of said casingbordering said slot.
 3. The invention defined by claim 1 in which saidfirst anchoring tab comprises an ear defined by an incision in theleading end portion of said leader member from which it extends, saidear being folded out of the plane said last-mentioned leading endportion.
 4. The invention defined by claim 2 in which said other leadermember is provided with a second anchoring tab corresponding to saidfirst anchoring tab, said second anchoring tab being initiallypositioned in facial engagement with the tip portion of said firstanchoring tab extending through said opening in said one leader member.5. The invention defined by claim 4 in which said first and secondanchoring tabs are initially sandwiched between said internal surface ofsaid casing and a surface defined by the adjacent end of said pressureplate means.
 6. The invention defined by claim 3 in which said firstanchoring tab is located along an imaginary longitudinal center line ofsaid first leader member.
 7. The invention defined by claim 1 in whichsaid other leader member is provided with two of such first anchoringtabs located at opposite edges thereof in transverse alignment with eachother.